James and Oliver Phelps are best known for playing Fred and George Weasley in the Harry Potter movies.
And it seems the twins were seen as such a unit in the movies that the Phelps brothers were not hired individually to play specific roles, but simply hired together to play Fred and George.
Fred and George Weasley are a nearly inseparable duo in the books and movies, that it becomes intentionally difficult to tell the two of them apart.
And initially it wasn’t even decided who would play who.